The church was originally built outside the walls and dedicated to the SS. Apostles Peter and Paul. In the seventeenth century it was demolished because it was in a difficult place to reach with bad weather and snow and the current church was built inside the walls by extending a previous building.
Today it is dedicated to the patron saint of Fiuggi. The new church in Baroque style has a Latin cross-shaped plan with a large nave and six side altars. It was inaugurated in 1617 as a collegiate, and rearranged as a college of priests.
Next to the church there is a sloping bell tower, which is accessed from the Castle Square, and was the original castle watch tower.